Vertically aligned carbon nanotubes based materials for High Energy Hybrid ultraCAPacitors – H2E-CAP

The lack of fossil fuels (oil, coal and natural gas) associated with growing energy needs of human populations, lead to increased costs of these energies. Moreover, their massive use causes environmental problems (air pollution, greenhouse effect etc ...) strongly affecting life conditions and health of populations. In this context of renewable energies promotion and gas emissions reduction the bottleneck of electricity storage is one of the biggest challenge that we have to address. One of the obstacles in transportation (urban or military) is the use of autonomous electrical power sources (rechargeable batteries, fuel cells, etc.). These devices do not allow for high enough specific powers, needed for the different type of applications they are expected for and limit their dynamical performances. For several years, developments have been achieved and have led to the development of ultracapacitors. These components are characterized by much higher specific energies compared to classical capacitors as well as higher specific powers compared to electrochemical batteries. However, their specific energy remains lower than batteries by a factor of 10 to 30. In this context, this fundamental project deals with the development of new high energy density hybrid ultracapacitors for specific applications both in the military and civil field. The development of new materials with improved specific capacitance associated with an increase in the potential difference applied during charging aims at increasing the performance in terms of energy density while maintaining a high power density. To do this, we will develop new pseudocapacitive positive electrode materials based on vertically aligned carbon nanotubes (VACNT) modified by electronic conducting polymers (ECP) and/or manganese oxide electrodeposited in a controlled manner. These new nanostructured electrodes will be associated within symmetric or asymmetric configuration with classical graphite electrode or titanate ones in order to ensure large charge-discharge currents and reach high power electrochemical hybrid ultracapacitors. Moreover this project reveals a high economical potential with the demonstration of low cost large surface VACNT production that will be exploited very soon by the NAWATechnologies Company under creation. That is why we propose, at the end of the project, the fabrication of a 10*10 cm2 ultracapacitor prototype using the best configuration to demonstrate industrialization feasibility of the concept.